Carl Horowitz

**University of Michigan**

Runs his own tutoring company

Carl taught upper-level math in several schools and currently runs his own tutoring company. He bets that no one can beat his love for intensive outdoor activities!

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In Algebra II and in the real world, sometimes we need to solve tax math problems by using linear equations. When solving word problems using linear equations, we first need to pull out the relevant information and put it into equation form. When working with **tax math problems**, we are usually asked to calculate sales tax rates or the total cost of an item with tax.

So here we're dealing with a word problem, I phone costs $300 there's tax rate of 8 percent how much do you have to spend in order to walk out the door with your new iPhone?

So this is a classic example of a linear equation dealing with tax okay, how tax works is you buy something and then you have to pay a certain amount of tax on it government takes that does whatever they do with it and then you walk out with your new toy.

So how I tend to look at this is you basically are paying for two things, you're paying for your original item whatever that retail value is and then you're paying for your tax rate as well and that's going to be what you have to pay. So for this particular example our iPhone is 300 dollars, that's our original price okay.

Tax rate, tax rate is just a set percentage of whatever you buy so in this case we're talking 8 percent so we're just going to pay 8 percent of 300 dollars. 8 percent as a decimal is 0.08 add that together so we add our tax amount to our original amount and that's going to be our total.

8 percent of 300, 8 times 3 is 24 accommodate for your decimal so this just turns out to be 24. 300+24 is 324. So in order to purchase a $300 iPod sorry iPhone you actually have to end up spending $24 in tax resulting in a payment of $324.